Ectoparasite control has been a goal of mankind throughout history. Devices having insecticidal activity and designed for use on animals such as livestock, companion animals and the like have been known for some years. For example, there are a number of commercially-available devices such as livestock ear tags which comprise an insecticide dispersed throughout a plasticized thermoplastic matrix. Examples of such devices are Terminator.TM. (available from Fermenta) and Tomahawk.TM. (available from Coopers). Thermoplastic devices such as the foregoing typically weigh 10 grams or more and contain substantial amounts of plasticizer.
Further, U.S. Pat. No. 4,195,075 which discloses an insecticidal livestock ear tag comprising a plasticized thermoplastic matrix also discloses that thermoset matrices such as a polyurethane are useful. In such an embodiment, the particular insecticide disclosed in said patent is said to act as an external plasticizer.
The prior art has not taught an antiectoparasite device comprising a bioactive agent incorporated in a radiation-cured thermoset resin.